What is electronics?

Electronics refers to the flow of charge (moving electrons) through nonmetal conductors (mainly semiconductors), whereas electrical refers to the flow of charge through metal conductors. An electronic element is any physical unit in an electronic system whose meaning is to affect the electrons or their related fields in a preferred way

consistent with the proposed function of the electronic system.

Components are generally anticipated to be in mutual electromechanical contact, usually by being soldered to a printed circuit board (PCB), to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Components may be packaged individually or in more complex groups as integrated circuits. Some common electronic components are capacitors, resistors, diodes, transistors, etc.

Electronics is different from electrical and electro-mechanical science and technology, which pact with the generation, distribution, switching, storage and conversion of electrical energy to and from other energy forms using wires, motors, generators, batteries, switches, relays, transformers, resistors and other passive components.

Electric charge is a physical property of substance which causes it to experience a force when near other electrically charged substance. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual disgusting force, as do two negatively charged objects. Positively charged entity

and negatively charged entity experience an attractive force. The SI unit of electric charge is the coulomb (C).

An atom is a particle of substance that individually defines a chemical element. An atom consists of a innermost nucleus that is usually bordered by one or more electrons. Each electron is negatively charged. The nucleus is positively charged, and encloses one or more comparatively important particles known as protons and neutrons.

The total mass of an atom, counting the protons, neutrons and electrons, is the atomic mass or atomic weight. Electrons donate only a tiny part of this mass. For most practical reason, the atomic weight can be thought of as the number of protons plus the number of neutrons. Because the number of neutrons in an atom can vary, there can be several different atomic weights for most elements.

Atoms having the same number of protons, but different numbers of neutrons, characterize the same element, but are known as different isotopes of that element. The isotope for an element is specified by the addition of the number of protons and neutrons.

Protons and electrons have equal and opposite charge, and normally an atom has equal numbers of both. Thus, atoms are frequently neutral. Anion is an atom with extra electrons or with a need of electrons, resulting in its being electrically charged. An ion with extra electrons is negatively charged and is called an anion; an ion lacking in electrons is positively charged and is called a cat ion.